The present invention relates to a milking apparatus including a fluid control valve system having in fluid communication a controller unit, a collection jar, and a discharge valve, and more particularly, a fluid control valve system having a vacuum sensing means for signaling the controller unit to close the discharge valve when fluid from the collection jar has been completely discharged through the discharge valve.
It is known in the prior art to have a milking apparatus which includes a valve unit, a collection jar and a discharge valve, all in fluid communication. A source of vacuum is provided in communication with the valve unit and with a discharge line of the discharge valve. Further the collection jar is provided in fluid communication with a claw unit having four teat cups, which teat cups are positionable for drawing milk from, for example, the udder of the cow. Generally the claw unit is associated with a flow meter which provides a signal for regulating the strength of the source of vacuum. When the volume of milk flowing from the cow diminishes to a given point, the flow meter signals a regulator associated with the source of vacuum, thereby initiating a reduction in the strength of the vacuum provided to the valve unit, to the collecting jar and to the claw for drawing milk from the udder of a cow. Such reduction in the amount of vacuum is necessary so that the cow udder does not become irritated, which irritation can give rise to udder disorders.
In the collection jar, the collected milk can be inspected and there are provisions incorporated into the discharge valve for sampling the collected milk. Once the milk collected in the collection jar has been inspected, the milk can be dumped through the discharge valve to a receiving jar by first closing a first conduit which provides communication between the source of vacuum and the valve unit and opening a second conduit so that the valve unit and the collecting jar are exposed to atmospheric pressures. Then, the discharge valve is opened and the source of vacuum draws the milk from the collection jar through the discharge valve into the receiving jar.
In order to reset the milking apparatus for milking another cow, the discharge valve must be closed and the collection jar must again be placed in communication with the source of vacuum, the conduit providing communication between the atmosphere and the valve unit also must be closed. The above-indicated procedure requires time to accomplish, time which the operator might more profitably spend, for example, preparing the next cow for milking or performing one of the other functions required during the milking operation. Further, as often is the case, the operator will inadvertently forget to close the discharge valve after the collection jar has been completely emptied of milk. The operator will, however, preparatory to milking the next cow, place the source of vacuum in communication through the valve unit, and thus with the collection jar and with the claw unit. As milking of a second cow begins, it can be seen that since the discharge valve still communicates with the collection jar, that the milk will flow from the claw unit through the collection jar and through the discharge valve to the receiving jar. While such a procedure might be acceptable when there is no need to inspect the milk drawn from the cow, prior to the transfer of the milk from the collection jar to the receiving jar, it is highly undesirable to have the discharge valve and thus the collection jar in communication with the source of vacuum as the flow of milk from the cow is diminishing. The reason for this is that even though the strength of the vacuum provided through the valve unit will be diminished by the regulator as the flow of milk diminishes, so as to prevent udder disorder, the strength of the vacuum provided through the discharge valve which is inadvertently provided in communication with the claw unit will not be diminished. Thus, the inadvertence of the operator in leaving the discharge valve open, will cause an undiminished source of vacuum to continue drawing milk from the udder. With vacuum so provided to the claw unit, the cow udder will become irritated and thus udder disorders are likely.
Another problem associated with prior art devices is that not only, as has been previously described, is there no provision for automatically closing the discharge valve preparatory to the next milking, but also there is no provision for automatically and immediately closing said discharge valve after milk from the collection jar has passed therethrough. Such an arrangement is necessary to prevent slugs of air from the collection jar from being drawn into the receiving jar, causing the milk therein to spin around at a rapid rate.
Further, the prior art milking apparatus has a valve unit which comprises a plurality of valves provided in communication with appropriate conduits. Use of such valves, such valves not being in a compact unit, proves sometimes to be troublesome. Further, there is a possibility that the valves could be incorrectly connected and that although correctly connected, could be inadvertently and mistakenly disconnected during operation.
Further, it is noted that during a sampling mode wherein samples of the milk collected in the collection jars are taken and the washing mode wherein the entire milking apparatus is washed, the above-indicated valves must be operated, although in a different sequential order. Thus, the operator must remember the operating orders for the valves for the sampling, and the cleaning modes, as well as the previously described milking mode.